The present study aimed to explore the expression and clinical significance of microRNA-21 (miR-21), maspin and vascular endothelial growth factor C (VEGF-C) in bladder cancer (BC). A total of 53 BC samples and 12 normal bladder tissue samples were collected. Total messenger RNA (mRNA) was extracted, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to evaluate the expression of miR-21 and maspin in BC and normal bladder tissues. Immunohistochemistry was used for the detection of maspin and VEGF-C protein expression. Furthermore, the correlations between these molecules and certain clinicopathological parameters were investigated, and survival analysis was performed to assess their prognostic significance. miR-21 mRNA expression and VEGF-C protein expression were increased in BC tissues compared with those in normal bladder tissues, whereas maspin mRNA and protein expression levels in BC tissues were significantly decreased (P<0.01). miR-21, maspin and VEGF-C expression were significantly associated with the stage, grade and lymph node metastasis of BC (P<0.05), but not the other clinicopathological features evaluated. There was a marked inverse correlation between the mRNA expression of miR-21 and maspin, with a coefficient of -0.978 (P<0.001). Similarly, there was a significant inverse correlation between the protein expression of maspin and VEGF-C, with a coefficient of -0.589 (P<0.001). Overexpression of miR-21 and VEGF-C, as well as decreased maspin expression, were associated with a poorer prognosis. These results suggested that upregulation of miR-21, decreased maspin expression and enhanced VEGF-C in BC may promote tumor progression. miR-21, maspin and VEGF-C may therefore have significant roles as biomarkers for prognosis and as therapeutic targets of BC.
Keywords: bladder cancer; maspin; microRNA-21; vascular endothelial growth factor C.